This invention relates generally to a braking system for vehicles and, more particularly to such a braking system employing eddy current generating rotatable magnets.
Disclosed in Japanese Patent Application No. 218498/1989, is an eddy-current type braking system in which a magnet supporting ring retains a number of permanent magnets in an equally spaced relationship juxtaposed internally of a brake drum. The magnet supporting ring is axially moved between a braking position in which the magnets exert a magnetic field on the inner cylindrical surface of the brake drum and a non-braking position in which the magnets do not exert a magnetic field on the inner cylindrical surface of the brake drum. In this eddy-current type reduction gear, an axial dimension of the fixed frame is relatively long producing difficulties in certain cases as when a reduction gear together with a parking brake are arranged in a narrow mounting space of a connecting portion between an output rotational shaft of a transmission and a propeller shaft under the floor of a vehicle.
The object of the present invention, therefore, is to provide an eddy-current type braking apparatus exhibiting an axial dimension shorter than prior art devices.